There was no users left - so drop the code to support EARLY_EVENT_BLANK.
This patch removes the support in backlight,
and drop the notifier in fbmem.
That EARLY_EVENT_BLANK is not used can be verified that no driver set any of:
    lcd_ops.early_set_power()
    lcd_ops.r_early_set_power()
Noticed while browsing backlight code for other reasons.
v2:
- Fix changelog to say "EARLY_EVENT_BLANK" (Daniel)
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190725143224.GB31803@ravnborg.org
                if (event == FB_EVENT_BLANK) {
                        if (ld->ops->set_power)
                                ld->ops->set_power(ld, *(int *)evdata->data);
-               } else if (event == FB_EARLY_EVENT_BLANK) {
-                       if (ld->ops->early_set_power)
-                               ld->ops->early_set_power(ld,
-                                               *(int *)evdata->data);
-               } else if (event == FB_R_EARLY_EVENT_BLANK) {
-                       if (ld->ops->r_early_set_power)
-                               ld->ops->r_early_set_power(ld,
-                                               *(int *)evdata->data);
                } else {
                        if (ld->ops->set_mode)
                                ld->ops->set_mode(ld, evdata->data);
 
 fb_blank(struct fb_info *info, int blank)
 {      
        struct fb_event event;
-       int ret = -EINVAL, early_ret;
+       int ret = -EINVAL;
 
        if (blank > FB_BLANK_POWERDOWN)
                blank = FB_BLANK_POWERDOWN;
        event.info = info;
        event.data = ␣
 
-       early_ret = fb_notifier_call_chain(FB_EARLY_EVENT_BLANK, &event);
-
        if (info->fbops->fb_blank)
                ret = info->fbops->fb_blank(blank, info);
 
        if (!ret)
                fb_notifier_call_chain(FB_EVENT_BLANK, &event);
-       else {
-               /*
-                * if fb_blank is failed then revert effects of
-                * the early blank event.
-                */
-               if (!early_ret)
-                       fb_notifier_call_chain(FB_R_EARLY_EVENT_BLANK, &event);
-       }
 
        return ret;
 }
 
 
 /*      A display blank is requested       */
 #define FB_EVENT_BLANK                  0x09
-/*      A hardware display blank early change occurred */
-#define FB_EARLY_EVENT_BLANK           0x10
-/*      A hardware display blank revert early change occurred */
-#define FB_R_EARLY_EVENT_BLANK         0x11
 
 struct fb_event {
        struct fb_info *info;
 
        /* Get the LCD panel power status (0: full on, 1..3: controller
           power on, flat panel power off, 4: full off), see FB_BLANK_XXX */
        int (*get_power)(struct lcd_device *);
-       /*
-        * Enable or disable power to the LCD(0: on; 4: off, see FB_BLANK_XXX)
-        * and this callback would be called proir to fb driver's callback.
-        *
-        * P.S. note that if early_set_power is not NULL then early fb notifier
-        *      would be registered.
-        */
-       int (*early_set_power)(struct lcd_device *, int power);
-       /* revert the effects of the early blank event. */
-       int (*r_early_set_power)(struct lcd_device *, int power);
        /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
        int (*set_power)(struct lcd_device *, int power);
        /* Get the current contrast setting (0-max_contrast) */